Moderate chronic sleep perturbation impairs glucose and lipid homeostasis in rats.

STUDY OBJECTIVES: Sleep deprivation is a potential risk factor for metabolic diseases, including obesity and type 2 diabetes. We evaluated the impacts of moderate chronic sleep deprivation on glucose and lipid homeostasis in adult rats. METHODS: Wistar rats (both sexes) were sleep-perturbed daily for 2 hours at the early (06:00-08:00) and the late light cycle (16:00-18:00) five days a week (except weekends) for 4 weeks. RESULTS: Sleep perturbation (SP) resulted in reduced body weight gain in both sexes, associated with altered food intake and reduced adiposity. SP did not alter the short- or long-term memories or cause anxiogenic behavior. No major changes were observed in the plasma insulin, leptin, triacylglycerol, non-esterified fatty acids, and blood glucose upon SP. After SP, females exhibited a transitory glucose intolerance, while males became glucose intolerant at the end of the experimental period. Male rats also developed higher insulin sensitivity at the end of the SP protocol. Morphometric analyses revealed no changes in hepatic glycogen deposition, pancreatic islet mass, islet-cell distribution, or adrenal cortex thickness in SP rats from both sexes, except for lower adipocyte size compared with controls. We did not find homogeneous changes in the relative expression of circadian and metabolic genes in muscle or hepatic tissues from the SP rats. CONCLUSIONS: Moderate chronic SP reduces visceral adiposity and causes glucose intolerance with a more pronounced impact on male rats, reinforcing the metabolic risks of exposure to sleep disturbances.

Hypoxia Induces Alterations in the Circadian Rhythm in Patients with Chronic Respiratory Diseases.

The function of the circadian cycle is to determine the natural 24 h biological rhythm, which includes physiological, metabolic, and hormonal changes that occur daily in the body. This cycle is controlled by an internal biological clock that is present in the body's tissues and helps regulate various processes such as sleeping, eating, and others. Interestingly, animal models have provided enough evidence to assume that the alteration in the circadian system leads to the appearance of numerous diseases. Alterations in breathing patterns in lung diseases can modify oxygenation and the circadian cycles; however, the response mechanisms to hypoxia and their relationship with the clock genes are not fully understood. Hypoxia is a condition in which the lack of adequate oxygenation promotes adaptation mechanisms and is related to several genes that regulate the circadian cycles, the latter because hypoxia alters the production of melatonin and brain physiology. Additionally, the lack of oxygen alters the expression of clock genes, leading to an alteration in the regularity and precision of the circadian cycle. In this sense, hypoxia is a hallmark of a wide variety of lung diseases. In the present work, we intended to review the functional repercussions of hypoxia in the presence of asthma, chronic obstructive sleep apnea, lung cancer, idiopathic pulmonary fibrosis, obstructive sleep apnea, influenza, and COVID-19 and its repercussions on the circadian cycles.

The sensory effects of light on the electric organ discharge rate of Gymnotus omarorum.

Gymnotiformes are nocturnal fishes inhabiting the root mats of floating plants. They use their electric organ discharge (EOD) to explore the environment and to communicate. Here, we show and describe tonic and phasic sensory-electromotor responses to light distinct from indirect effects depending on the light-induced endogenous circadian rhythm. In the dark, principally during the night, inter-EOD interval histograms are bimodal: the main peak corresponds to the basal rate and a secondary peak corresponds to high-frequency bouts. Light causes a twofold tonic but opposing effect on the EOD histogram: (i) decreasing the main mode and (ii) blocking the high-frequency bouts and consequently increasing the main peak at the expense of removal of the secondary one. Additionally, light evokes phasic responses whose amplitude increases with intensity but whose slow time course and poor adaptation differentiate from the so-called novelty responses evoked by abrupt changes in sensory stimuli of other modalities. We confirmed that Gymnotus omarorum tends to escape from light, suggesting that these phasic responses are probably part of a global 'light-avoidance response'. We interpret the data within an ecological context. Fish rest under the shade of aquatic plants during the day and light spots due to the sun's relative movement alert the fish to hide in shady zones to avoid macroptic predators and facilitate tracking the movement of floating plant islands by wind and/or water currents.

Relationship between nocturnal enuresis and sleep in children and adolescents.

BACKGROUND: Nocturnal enuresis (NE) is a multifactorial and complex condition. One less understood factor in its pathophysiology is the enuretic inability to wake up when the bladder is full (impaired arousal). OBJECTIVE: We aimed to investigate the relationship between sleep and NE in children and adolescents. METHODS: A systematic review was performed following the PRISMA guidelines, and the electronic databases MEDLINE (via PubMed) and SCOPUS were searched until March 2022. Eligibility criteria were studies that recruited patients aged five-17 years with a diagnosis of NE according to the International Child Continence Society (ICCS), Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5), or International Classification Criteria of Sleep Disorders-Third edition (ICSD-3) who had their sleep assessed using validated questionnaires and/or polysomnography. The tool used to analyze the risk of bias in the included studies was the risk of bias in non-randomized studies of exposure. RESULTS: Of 1582 citations screened, nine were included, giving 1685 participants, 581 with NE. All studies were observational and half had a low risk of bias. Four studies evaluated sleep by questionnaires only; two used questionnaires and polysomnography; two used only polysomnography, and one used sleep logs and actigraphy. Sleep questionnaires showed that children with enuresis had more sleep problems than controls, especially parasomnias, breathing disorders, and daytime sleepiness. Among the polysomnography parameters, the sleep stage architecture and periodic limb movements during sleep had conflicting data between the two studies. LIMITATIONS: The studies evaluated sleep through heterogeneous tools. They used different questionnaires; even those considered by polysomnography did not record the same channels. CONCLUSION: It seems that enuretic children and adolescents sleep differently from those who are non-enuretic. More studies are needed to clarify the best way to assess sleep and better understand this relationship. The review protocol was registered with PROSPERO, CRD42021266338. There was no funding.

Bioluminescent Dinoflagellates as a Bioassay for Toxicity Assessment.

Dinoflagellates bioluminescence mechanism depends upon a luciferin-luciferase reaction that promotes blue light emission (480 nm) in specialized luminogenic organelles called scintillons. The scintillons contain luciferin, luciferase and, in some cases, a luciferin-binding protein (LBP), which prevents luciferin from non-enzymatic oxidation in vivo. Even though dinoflagellate bioluminescence has been studied since the 1950s, there is still a lack of mechanistic understanding on whether the light emission process involves a peroxidic intermediate or not. Still, bioassays employing luminous dinoflagellates, usually from Gonyaulax or Pyrocystis genus, can be used to assess the toxicity of metals or organic compounds. In these dinoflagellates, the response to toxicity is observed as a change in luminescence, which is linked to cellular respiration. As a result, these changes can be used to calculate a percentage of light inhibition that correlates directly with toxicity. This current approach, which lies in between fast bacterial assays and more complex toxicity tests involving vertebrates and invertebrates, can provide a valuable tool for detecting certain pollutants, e.g., metals, in marine sediment and seawater. Thus, the present review focuses on how the dinoflagellates bioluminescence can be applied to evaluate the risks caused by contaminants in the marine environment.

Re-exposures in the Dark Cycle Promote Attenuation of Fear Memory: Role of the Circadian Cycle and Glucocorticoids.

It has been shown that a previously consolidated memory can incorporate either new external information or a novel internal emotional state following a labile state induced by retrieval. This updating process allows editing unwanted fear memory, leading to the reduction of the fear response. Memory can be modulated by the circadian cycle. Considering that rodents are more active during the night, expressing less fearful behavior, we investigated whether fear memory can be updated when reactivated during the dark cycle. We found that rats expressed lower freezing levels during a single retrieval session in the dark cycle, but not in the test. However, three retrieval sessions in the dark cycle were able to update fear memory, reducing freezing response in the test performed in the light cycle. This effect was blocked when the glucocorticoid synthesis inhibitor metyrapone was administered before retrieval. This approach opens new avenues to explore interventions that consider the circadian cycle in the treatment of fear memories based on non-pharmacological interventions.

Perception and sensory acceptance of sweet taste by individuals that who work/study on different shifts / Percepção e aceitação sensorial do gosto doce por indivíduos que trabalham/estudam em diferentes turnos

ABSTRACT Objective This study aimed to evaluate the perception and sensory acceptance of sweet taste by individuals who work/study on different shifts. Methods Three groups of individuals were recruited: the Control group (individuals that study during the day and do not work at night), Group 1 (individuals that study in the evening) and Group 2 (individuals that work overnight). The individuals were submitted to a detection threshold test using sucrose solutions and a sensory acceptance test using a structured hedonic scale and a Just-About-Right scale for sweet taste in blancmange. Results The detection thresholds were significantly higher for Groups 1 and 2. Individuals of Group 2 had a preference by blancmanges when having high sucrose concentrations, as well as had an ideal concentration of 10.50% sucrose against 5.95% sucrose for the Control group. Conclusion Our study shows a relationship between changes in the circadian cycle and the sensory perception and acceptance of sweet taste. More studies need to be performed to understand such relationships and their repercussions better.

RESUMO Objetivo O objetivo deste estudo foi avaliar a percepção e a aceitação sensorial do gosto doce por indivíduos que trabalham/estudam em diferentes turnos. Métodos Foram recrutados três grupos de indivíduos: Grupo Controle (indivíduos que estudam durante o dia e não trabalham à noite), Grupo 1 (indivíduos que estudam à noite) e Grupo 2 (indivíduos que trabalham de madrugada). Os indivíduos foram submetidos ao teste de limiar de detecção utilizando soluções de sacarose e aos testes de aceitação sensorial utilizando escala hedônica estruturada e escala do ideal para o gosto doce em manjar branco. Resultados Os limiares de detecção foram significativamente maiores para os Grupos 1 e 2, sendo certo que os indivíduos do Grupo 2 tiveram preferência pelos manjares com altas concentrações de sacarose, assim como apresentaram uma concentração ideal de 10,50% de sacarose contra 5,95% de sacarose para o grupo Controle. Conclusão Este estudo mostra uma relação entre mudanças no ciclo circadiano e a percepção e a aceitação sensorial do gosto doce, mostrando que estudos mais aprofundados precisam ser realizados para entender melhor tais relações e suas repercussões.

Genetic association of the PERIOD3 (PER3) Clock gene with extreme obesity.

BACKGROUND: Obesity has reached epidemic proportions worldwide, affecting life quality and span. Susceptibility to obesity is partly mediated by genetic differences. Indeed, several genes from the clock gene family have already been shown to be intimately associated with obesity in diverse ethnic groups. In the present study, an association between BMI and the rs707467, rs228697 and rs228729 PER3 (Period Circadian Clock 3) polymorphisms in subjects with class II (BMI ≥ 35.0-39.9 kg/m2) and class III obesity (>40 kg/m2, extreme obesity) were carried out using TaqMan real-time PCR. Overall, 259 Brazilian adults were genotyped, of whom 122 had class II or III obesity (BMI ≥ 35.0 kg/m2) and 137 were controls having normal weight (BMI > 18.5 and <24.9 kg/m2). RESULTS: PER3 tag SNP (rs228729) shows a significant association with extreme obesity (1000 permutation p = 0.03 and p = 0.04), for genotype and allele frequency respectively) and a haplotype among the three assessed SNPs (alleles G/T/A, rs228697, rs228729, and rs707467, respectively, 1000 permutation p = 0.03) was significantly more prevalent in the group with obesity. CONCLUSION: This exploratory association study suggests that PER3 rs228729 may be associated with extreme obesity in Brazilian adults, however, replication is needed.

The Time for Chronotherapy in Radiation Oncology.

Five decades ago, Franz Halberg conceived the idea of ​​a circadian-based therapy for cancer, given the differential tolerance to treatment derived from the intrinsic host rhythms. Nowadays, different experimental models have demonstrated that both the toxicity and efficacy of several anticancer drugs vary by more than 50% as a function of dosing time. Accordingly, it has been shown that chemotherapeutic regimens optimally timed with the circadian cycle have jointly improved patient outcomes both at the preclinical and clinical levels. Along with chemotherapy, radiation therapy is widely used for cancer treatment, but its effectiveness relies mainly on its ability to damage DNA. Notably, the DNA damage response including DNA repair, DNA damage checkpoints, and apoptosis is gated by the circadian clock. Thus, the therapeutic potential of circadian-based radiotherapy against cancer is mainly dependent upon the control that the molecular clock exerts on DNA repair enzymes across the cell cycle. Unfortunately, the time of treatment administration is not usually considered in clinical practice as it varies along the daytime working hours. Currently, only a few studies have evaluated whether the timing of radiotherapy affects the treatment outcome. Several of these studies show that it is possible to reduce the toxicity of the treatment if it is applied at a specific time range, although with some inconsistencies. In this Perspective, we review the main advances in the field of chronoradiotherapy, the possible causes of the inconsistencies observed in the studies so far and provide some recommendations for future trials.

Extended light period in the maternal circadian cycle impairs the reproductive system of the rat male offspring.

Alterations in the circadian cycle are known to cause physiological disorders in the hypothalamic-pituitary-adrenal and the hypothalamic-pituitary-gonadal axes in adult individuals. Therefore, the present study aimed to evaluate whether exposure of pregnant rats to constant light can alter the reproductive system development of male offspring. The dams were divided into two groups: a light-dark group (LD), in which pregnant rats were exposed to an LD photoperiod (12 h/12 h) and a light-light (LL) group, in which pregnant rats were exposed to a photoperiod of constant light during the gestation period. After birth, offspring from both groups remained in the normal LD photoperiod (12 h/12 h) until adulthood. One male of each litter was selected and, at adulthood (postnatal day (PND) 90), the trunk blood was collected to measure plasma testosterone levels, testes and epididymis for sperm count, oxidative stress and histopathological analyses, and the spermatozoa from the vas deferens to perform the morphological and motility analyses. Results showed that a photoperiod of constant light caused a decrease in testosterone levels, epididymal weight and sperm count in the epididymis, seminiferous tubule diameter, Sertoli cell number, and normal spermatozoa number. Histopathological damage was also observed in the testes, and stereological alterations, in the LL group. In conclusion, exposure to constant light during the gestational period impairs the reproductive system of male offspring in adulthood.

Physiological responses and thermal equilibrium of Jersey dairy cows in tropical environment.

Long-term assessments of thermal responses of housed Jersey cows raised in tropical conditions were performed to investigate the effect of climate environment on their physiological performance and thermal equilibrium. Twelve Jersey dairy cows with 326.28 ± 30 kg of body weight, 17.66 ± 1.8 of milk yield, and 165.5 ± 6.8 of days in milking were assigned in two 12 × 12 Latin square designs. Air temperature, relative humidity, partial vapor pressure, direct and diffuse short-wave solar radiation and black globe temperature under the shade, and direct sunlight were recorded. Physiological responses as respiratory rate (RR, breaths min-1), ventilation (VE, L s-1), proportion (%) of oxygen (O2) and carbon dioxide (CO2), saturation pressure (PS{TEXH}), and air temperature (TEXH, °C) of the exhaled air were assessed protected from solar radiation and rain. Rectal temperature (TR, °C), skin temperature (TEP, °C), and hair coat surface temperature (TS, °C) were also recorded. The thermal equilibrium was determined from biophysical equations according to the principles of the energy conservation law in a control volume. Exploratory and confirmatory analyses were performed from principal components and by the least square method, respectively. The cows were evaluated under range of ambient air temperature from 26 to 35 °C, relative humidity from 27 to 89%, and short-wave radiation from 0 to 729 W m-2. Exploratory and confirmatory analyses demonstrated that a similar level of nocturnal and diurnal air temperatures evoked distinct (P < 0.05) responses for rectal (TR, °C) and skin (TEP, °C) temperatures, ventilation (VE, L s-1), tidal volume (TV, L breaths-1), and oxygen consumption (∆O2, %) and carbon dioxide output (∆CO2, %), clearly revealing an endogenous rhythm dependence. In conclusion, these findings clarify how the circadian rhythmicity of the thermal environment and animal's biological clock dictate dynamics of heat generated by metabolism, dissipated to the environment and physiological parameters of the housed Jersey cows raised in tropical condition; therefore, it is fundamental to help us to understand how the Jersey dairy cows under tropics are affected by the climatic conditions, leading to better ways of the environmental management.

El sueño del niño con trastornos del neurodesarrollo / The sleep in children with neurodevelopmental disorders

El sueño adecuado es necesario para el desarrollo sináptico y la maduración cerebral, un sueño de mala calidad tiene efectos perjudiciales en las funciones cognitivas, de atención, memoria y conducta de los niños. La preocupación sobre la alta prevalencia de los problemas del sueño es amplia en todo el mundo; las consecuencias de estos problemas son incluso más importantes en los niños portadores de trastornos del neurodesarrollo; estos niños a menudo tienen dificultades de inicio y mantenimiento del sueño y despertares nocturnos frecuentes que afectan a sus problemas de conducta. El propósito de este escrito es revisar el estado del arte de los problemas del sueño en los niños con trastornos del neurodesarrollo. En este punto, es importante tener en cuenta el ritmo circadiano, un reloj que genéticamente dirige los ritmos celulares de transcripción, traslación y metabolismos. Este reloj se combina con el ambiente diurno y nocturno coordinando estos mecanismos durante los ciclos luz/oscuridad, sueño/vigilia, frío/calor, ingesta/ayuno, tanto diariamente como en las diferentes estaciones. En conclusión, los problemas del sueño son un factor condicionante de la evolución y calidad de vida de los niños con trastornos del neurodesarrollo, que debe ser tenido en cuenta en todos los casos y ocupar un lugar preferente tanto en la etapa diagnóstica como en la terapéutica.

Adequate sleep is of critical need for a typical synaptic development and brain maturation, a poor quality sleep can have detrimental effects on children's' cognitive attention, memory, mood regulation, and behavior functions. Great concern has been voiced out regarding the high prevalence of poor sleep in children worldwide, the effects of poor sleep may be even more pronounced in children with neurodevelopmental disorders; these children often have difficulties with falling and staying asleep and with night awakenings, this has a strong association with daytime behavior problems. The purpose of this article is to provide an overview of the state of the science of sleep in children with a neurodevelopmental disorder. In this context, it is important to take the circadian cycle into account, a genetically encoded clock that drives cellular rhythms of transcription, translation and metabolism. The circadian clock interacts with the diurnal and nocturnal environment that also drives transcription and metabolism during light/dark, sleep/wake, hot/cold and feast/fast daily and seasonal cycles In conclusion, the sleep problems are a conditioning factor in the evolution and quality of life of children with neurodevelopmental disorders that must be taken into account in all cases and occupy a preferential place in both the diagnostic and the therapeutic stages.

[The sleep in children with neurodevelopmental disorders]. / El sueño del niño con trastornos del neurodesarrollo.

Adequate sleep is of critical need for a typical synaptic development and brain maturation, a poor quality sleep can have detrimental effects on children's' cognitive attention, memory, mood regulation, and behavior functions. Great concern has been voiced out regarding the high prevalence of poor sleep in children worldwide, the effects of poor sleep may be even more pronounced in children with neurodevelopmental disorders; these children often have difficulties with falling and staying asleep and with night awakenings, this has a strong association with daytime behavior problems. The purpose of this article is to provide an overview of the state of the science of sleep in children with a neurodevelopmental disorder. In this context, it is important to take the circadian cycle into account, a genetically encoded clock that drives cellular rhythms of transcription, translation and metabolism. The circadian clock interacts with the diurnal and nocturnal environment that also drives transcription and metabolism during light/dark, sleep/wake, hot/cold and feast/fast daily and seasonal cycles In conclusion, the sleep problems are a conditioning factor in the evolution and quality of life of children with neurodevelopmental disorders that must be taken into account in all cases and occupy a preferential place in both the diagnostic and the therapeutic stages.

El sueño adecuado es necesario para el desarrollo sináptico y la maduración cerebral, un sueño de mala calidad tiene efectos perjudiciales en las funciones cognitivas, de atención, memoria y conducta de los niños. La preocupación sobre la alta prevalencia de los problemas del sueño es amplia en todo el mundo; las consecuencias de estos problemas son incluso más importantes en los niños portadores de trastornos del neurodesarrollo; estos niños a menudo tienen dificultades de inicio y mantenimiento del sueño y despertares nocturnos frecuentes que afectan a sus problemas de conducta. El propósito de este escrito es revisar el estado del arte de los problemas del sueño en los niños con trastornos del neurodesarrollo. En este punto, es importante tener en cuenta el ritmo circadiano, un reloj que genéticamente dirige los ritmos celulares de transcripción, traslación y metabolismos. Este reloj se combina con el ambiente diurno y nocturno coordinando estos mecanismos durante los ciclos luz/oscuridad, sueño/vigilia, frío/calor, ingesta/ayuno, tanto diariamente como en las diferentes estaciones. En conclusión, los problemas del sueño son un factor condicionante de la evolución y calidad de vida de los niños con trastornos del neurodesarrollo, que debe ser tenido en cuenta en todos los casos y ocupar un lugar preferente tanto en la etapa diagnóstica como en la terapéutica.

Relationship of self-reported sleep bruxism and awake bruxism with chronotype profiles in Italian dental students.

OBJECTIVES: A cross-sectional study was performed to assess the association between possible sleep bruxism (SB) and awake bruxism (AB) with sleep characteristics and chronotype (i.e. circadian cycle preference). METHODS: One-hundred-nineteen young adults filled out a self-reported questionnaire to assess SB and AB, a questionnaire about daily life aspects, as well as the Morningness-Eveningness Questionnaire (MEQ) to profile chronotype. RESULTS: The frequency of self-reported SB and AB was 25.2% and 37.0%, respectively. Both SB and AB were significantly more frequent in females than males. Most participants had an intermediate chronotype profile (n = 85; 71.4%). Neither SB (p = 0.556) nor AB (p = 0.334) were associated with chronotype. Nightmares were more prevalent among individuals with possible SB (38.3%). Difficulty concentrating in daily activities was more frequently reported among individuals with AB (51.9%). CONCLUSION: There was no association between possible SB and AB or the chronotype profiles among Italian dental students.

Monitoring whole blood, plasma and serum variables of Nile tilapia during 24 hours, after capture stress / Monitoramento das variáveis do sangue total, plasma e soro de Tilápia-do-Nilo, durante 24 horas, após estresse de captura

Stress is know as responsible for the decrease in immunity and reduced survival, growth, and reproductive capacity of animals. Besides, organisms respond to certain biological rhythms, such as circadian, to which animals naturally adjust. This study aimed to monitor the plasma (lactate and total protein), serum (cortisol and cholesterol) and whole blood (glucose) variables in tilapia in a 24 h cycle. A set of 49 aquariums with 5 individuals each were used. All of them, at the beginning of the experiment, were subjected to the same stress of capture and handling. The animals from the first aquaria were sampled after 15 min of stress. Blood samples from animals of the remaining aquarium were sequentially drawn at 30-min intervals. Radar charts were used to visualize the hourly change in the measured variables. Significant differences of each analysis between the measured variables by aquarium and the phases of the circadian cycle (light-dark) and morning-afternoon-night-dawn intervals, were evaluated using the Mann-Whitney and Kruskal-Wallis tests, respectively. A positive relationship between cortisol and glucose levels was found. Most analysis, except cholesterol and lactate did not show any significant difference between light and dark periods, and the intensity and frequency of peaks observed were not deleterious to individuals.(AU)

O estresse é conhecidamente responsável pela diminuição da imunidade e redução da sobrevivência, crescimento e capacidade reprodutiva dos animais. Além disso, os organismos respondem a certos ritmos biológicos, como o circadiano, aos quais se ajustam naturalmente. Este estudo teve como objetivo monitorar as variáveis plasmática (lactato e proteína total), soro (cortisol e colesterol) e sangue total (glicose) na tilápia em um período de 24 h. Quarenta e nove aquários com 5 indivíduos cada foram utilizados. Todos eles, no início do experimento, foram submetidos ao mesmo estresse de captura e manuseio. Os animais do primeiro aquários foram amostrados após 15 min do estresse. Os demais As amostras de sangue de indivíduos de cada aquário foram sequencialmente em intervalos de 30 min. Somente os indivíduos do primeiro aquário foram analisados após 15 minutos de estresse. Os gráficos de radar foram usadas para visualizar a variação horária nas variáveis medidas. Diferenças estatisticamente significativas entre a média dos indivíduos de cada aquário, para as fases do ciclo circadiano (luz-escuro) e os intervalos manhã-tarde-noite-madrugada foram respectivamente avaliadas utilizando os testes Mann-Whitney e Kruskal-Wallis. Observou-se relação positiva entre os níveis de cortisol e glicose. As análises, com exceção de colesterol e lactato, não mostraram diferença significativa entre períodos de luz e sombras, e a intensidade e a freqüência dos picos observados não foram prejudiciais aos indivíduos.(AU)

Monitoring whole blood, plasma and serum variables of Nile tilapia during 24 hours, after capture stress / Monitoramento das variáveis do sangue total, plasma e soro de Tilápia-do-Nilo, durante 24 horas, após estresse de captura

Stress is know as responsible for the decrease in immunity and reduced survival, growth, and reproductive capacity of animals. Besides, organisms respond to certain biological rhythms, such as circadian, to which animals naturally adjust. This study aimed to monitor the plasma (lactate and total protein), serum (cortisol and cholesterol) and whole blood (glucose) variables in tilapia in a 24 h cycle. A set of 49 aquariums with 5 individuals each were used. All of them, at the beginning of the experiment, were subjected to the same stress of capture and handling. The animals from the first aquaria were sampled after 15 min of stress. Blood samples from animals of the remaining aquarium were sequentially drawn at 30-min intervals. Radar charts were used to visualize the hourly change in the measured variables. Significant differences of each analysis between the measured variables by aquarium and the phases of the circadian cycle (light-dark) and morning-afternoon-night-dawn intervals, were evaluated using the Mann-Whitney and Kruskal-Wallis tests, respectively. A positive relationship between cortisol and glucose levels was found. Most analysis, except cholesterol and lactate did not show any significant difference between light and dark periods, and the intensity and frequency of peaks observed were not deleterious to individuals.

O estresse é conhecidamente responsável pela diminuição da imunidade e redução da sobrevivência, crescimento e capacidade reprodutiva dos animais. Além disso, os organismos respondem a certos ritmos biológicos, como o circadiano, aos quais se ajustam naturalmente. Este estudo teve como objetivo monitorar as variáveis plasmática (lactato e proteína total), soro (cortisol e colesterol) e sangue total (glicose) na tilápia em um período de 24 h. Quarenta e nove aquários com 5 indivíduos cada foram utilizados. Todos eles, no início do experimento, foram submetidos ao mesmo estresse de captura e manuseio. Os animais do primeiro aquários foram amostrados após 15 min do estresse. Os demais As amostras de sangue de indivíduos de cada aquário foram sequencialmente em intervalos de 30 min. Somente os indivíduos do primeiro aquário foram analisados após 15 minutos de estresse. Os gráficos de radar foram usadas para visualizar a variação horária nas variáveis medidas. Diferenças estatisticamente significativas entre a média dos indivíduos de cada aquário, para as fases do ciclo circadiano (luz-escuro) e os intervalos manhã-tarde-noite-madrugada foram respectivamente avaliadas utilizando os testes Mann-Whitney e Kruskal-Wallis. Observou-se relação positiva entre os níveis de cortisol e glicose. As análises, com exceção de colesterol e lactato, não mostraram diferença significativa entre períodos de luz e sombras, e a intensidade e a freqüência dos picos observados não foram prejudiciais aos indivíduos.

Potential Chronotherapeutic Optimization of Antimalarials in Systemic Lupus Erythematosus: Is Toll-Like Receptor 9 Expression Dependent on the Circadian Cycle in Humans?

Toll-like receptor 9 (TLR9) belongs to the group of endosomal receptors of the innate immune system with the ability to recognize hypomethylated CpG sequences from DNA. There is scarce information about TLR9 expression and its association with the circadian cycle (CC). Different patterns of TLR9 expression are regulated by the CC in mice, with an elevated expression at Zeitgeber time 19 (1:00 a.m.); nevertheless, we still need to corroborate this in humans. In systemic lupus erythematosus (SLE), the inhibitory effect of chloroquine (CQ) on TLR9 is limited. TLR9 activation has been associated with the presence of some autoantibodies: anti-Sm/RNP, anti-histone, anti-Ro, anti-La, and anti-double-stranded DNA. Treatment with CQ for SLE has been proven to be useful, in part by interfering with HLA-antigen coupling and with TLR9 ligand recognition. Studies have shown that TLR9 inhibitors such as antimalarial drugs are able to mask TLR9-binding sites on nucleic acids. The data presented here provide the basic information that could be useful for other clinical researchers to design studies that will have an impact in achieving a chronotherapeutic effect by defining the ideal time for CQ administration in SLE patients, consequently reducing the pathological effects that follow the activation of TLR9.

A glândula pineale sua importancia na reprodução e ciclos circadiano e migratório das aves marinhas - revisão de literatura

Nas aves, os marca-passos circadianos estão localizados no hipotálamo, na glândula pineal e/ou nos os olhos. Esta glândula exerce função de modulação endócrina e regulação de sistemas não endócrinos, quando estes sofrem a ação de alterações ambientais e/ou do próprio organismo. Ela é encarregada de monitorar as estações do ano e sincronizar com elas algumas funções que variam anualmente, como o comportamento reprodutor e migratório das aves. Desta forma, torna-se importante o estudo sobre a sua morfologia e como este conhecimento pode auxiliar na sobrevivência das aves marinhas.(AU)

In birds, circadian pacemakers are located in the hypothalamus, pineal gland and / or eyes. This gland exerts a function of endocrine modulation and regulation of non-endocrine systems, when they undergo environmental changes and / or the body itself. She is in charge of monitoring the seasons and synchronizing with them some functions that vary annually, such as the breeding and migratory behavior of the birds. In this way, it becomes important to study its morphology and how this knowledge can aid in the survival of seabirds.(AU)

A glândula pineale sua importancia na reprodução e ciclos circadiano e migratório das aves marinhas - revisão de literatura

Nas aves, os marca-passos circadianos estão localizados no hipotálamo, na glândula pineal e/ou nos os olhos. Esta glândula exerce função de modulação endócrina e regulação de sistemas não endócrinos, quando estes sofrem a ação de alterações ambientais e/ou do próprio organismo. Ela é encarregada de monitorar as estações do ano e sincronizar com elas algumas funções que variam anualmente, como o comportamento reprodutor e migratório das aves. Desta forma, torna-se importante o estudo sobre a sua morfologia e como este conhecimento pode auxiliar na sobrevivência das aves marinhas.

In birds, circadian pacemakers are located in the hypothalamus, pineal gland and / or eyes. This gland exerts a function of endocrine modulation and regulation of non-endocrine systems, when they undergo environmental changes and / or the body itself. She is in charge of monitoring the seasons and synchronizing with them some functions that vary annually, such as the breeding and migratory behavior of the birds. In this way, it becomes important to study its morphology and how this knowledge can aid in the survival of seabirds.

Pupal emergence pattern in cactophilic Drosophila and the effect of host plants.

Drosophila buzzatii and D. koepferae are sibling cactophilic species. The former breeds primarily on prickly pears (genus Opuntia) whereas the latter breeds on columnar cacti of the genera Cereus and Trichocereus, although with certain degree of niche overlapping. We examined the interspecific differences in diurnal temporal patterns of adult emergence from puparia and evaluated whether this behavior is affected by rearing in the different cactus hosts available in nature. We detected important host-dependent genetic variation for this trait differentially affecting the emergence schedule of these species. Diurnal pattern of emergence time was directly correlated with developmental time and negatively correlated with adult wing size, suggesting that early emergences are at least indirectly correlated with increased fitness. We discussed our results in terms of their putative effects on fitness and the genetic-metabolic pathways that would be presumably affected by host's nutritional-chemical differences.